In 1995, when the first “conference of the parties” (Cop) of the UN’s climate change convention met in Berlin, the atmospheric carbon dioxide concentration was approximately 360.67 parts per million. The then German chancellor, Helmut Kohl, gave a passionate speech about how greenhouse gases must be reduced to save the planet from overheating. There was a relatively unknown East German woman, the environment minister, Angela Merkel, chairing the conference. She was red hot at keeping order. The UK journalists concluded she would have a bright future.

Immediately after the conference I was commissioned to write a book about climate change called Global Warming: Can Civilization Survive? It sold well and was the first of several.

Scroll forward through Kyoto, Paris and the annual ritual of 30 years of Cops and the same speech Kohl made has been repeated, sometimes almost word for word, by prime ministers, presidents and campaigners year after year.

As I write, the carbon level – recorded daily in this paper – has reached 426.68 parts per million – well over scientists’ so called “safe” limit of 350. According to them, the planet is heading towards oblivion. All that time news editors have told me not to be too downbeat; let’s have some optimism.

This is my last column. I think the facts speak for themselves.